Field of the Invention
The invention relates to an encapsulated tubular conductor having at least two antenna elements disposed on the capsule for maintaining therebetween wireless information transmission in a transmitting-receiving direction, and a transmitting-receiving device located outside the capsule and being assigned to one of the antenna elements.
German Utility Model 94 20 199 discloses a metal-encapsulated high-voltage switching installation in which a surface acoustic wave element (SAW) is arranged in one of the gas regions thereof. The SAW is used for verifying gas constituents which are produced by the effect of arcing on the extinguishing gas which is contained in the encapsulation, or for detecting pressure waves. In this regard, an antenna, which is used for wireless information transmission to an evaluation device, is arranged on the outside of the encapsulation. The published German Patent Document DE 195 14 342 Cl discloses the use of SAW sensors in a high-voltage cable.
The use of SAW sensors in high-voltage technology is disclosed in principle in the article "Akustische Oberflachenwellen-Technologie fur Innovationen" [Surface acoustic wave technology for innovations] from Siemens-Zeitschrift Spezial (Siemens Journal, Special] FuE, Spring 1994. It has also already been provided in this case for the SAW sensor to be mounted in the container and for its antenna to be mounted externally.
For information transmission in high-voltage cables it is known, for example, for information to be transmitted via telecontrol cables or telephone lines. It is also known for the information which is to be transmitted to be input onto the high-voltage cable itself.
The European Patent Document EP-A-0 621 489 discloses a device for registering partial loads in a tubular conductor. For doing so, a registering device with antenna elements is provided inside the tubular conductor. It transmits information to another antenna element directed towards the interior which is connected with a processing device arranged outside of the tubular conductor. The arrangement described in this published document primarily serves for wireless interference value determination, transmission of information being provided for only in the message direction.